This is the ValueSet that contains all the codes in US Public Health PlanDefinition Action (http://hl7.org/fhir/us/medmorph/ValueSet/us-ph-plandefinition-action) and US Public Health VaueSet - PlanDefinition Action (http://hl7.org/fhir/us/ph-library/ValueSet/us-ph-valueset-plandefinition-action). E.g. what you have to deal with if you get resources containing codes in either of them